31results about How to "Reduce spurious signals" patented technology

Disclosed is an electrical interconnect system using multiple grounding methods to reduce or prevent spurious signals from interfering with high density contacts carrying high speed transmissions. A first connector includes an insulative pillar partially surrounded by a plurality of signal contacts. A ground contact is at least partially located within the insulative pillar. A second connector includes a corresponding plurality of flexible signal contacts for mating with the signal contacts adjacent the insulative pillar. The second connector also includes a ground contact for receiving the ground contact of the first connector. The ground contacts provide a first method of providing a ground path to reduce spurious signals from entering the signal path. An electrically conducting shield is located outside the signal contacts when the first and the second connectors are mated. The first connector includes a member which provides a ground path between the first connector and the electrically conducting shield. Advantageously, the electrical interconnect system has two grounding methods which are particularly important in a high density electrical interconnect system where the contacts are closely spaced and susceptible to noise and other spurious signals.

A modulator being made small in size, low in costs, low in power consumption, small in heat generation and spurious signals. The modulator includes multipliers (101, 102) for code-modulating received transmission data (D(n), C(n)), and outputting the modulated data, a control channel gain factor signal generator (106) for generating a gain control signal, a control channel gain factor signal generator (107), and weighting coefficient setting signal generators (108, 109) for receiving the output of the complex-number computing section (120) and controlling the gains of the raised cosine filters (110 to 113).

The invention discloses a high-temperature superconducting duplex subsystem which is packaged in a refrigerator in vacuum; and the operating temperature is kept to be lower than the transition temperature of a superconducting material. The high-temperature superconducting duplex subsystem comprises two radio frequency (RF) ports, a large-power superconducting filter, a first circulator, a second circulator, a receiving channel and a microwave element. The system is applied in a wireless system and can realize the situation of simultaneously receiving and sending wireless signals.

The invention provides a limited random frequency different reflection control method of a microwave signal. The limited random frequency different reflection control method of the microwave signal comprises the following steps: step 1, setting a frequency different signal, converting the frequency difference signal to a sin signal and a cos signal when the frequency different signal passes in a FPGA (Field Programmable Gata Array), and inputting the sin signal and the cos signal to a modulator; step 2, performing demodulation on a coupling power of an input signal, then processing the coupling power, controlling a voltage-controlled attenuator, and adjusting the voltage-controlled attenuator to a proper power range; step 3, setting a power of an output signal to realize stable amplitude control on a gain at an amplitude stabilizing ring. Due to the adoption of the limited random frequency different reflection control method, the offset of a carrier wave and the suppression of an image frequency can be effectively suppressed by a calibration modulator; a spurious signal is reduced, so that the phase noise worsening degree is constant in the process of changing the frequency in a whole channel, and the reliability is realized due to a small frequency difference.

The invention discloses a microwave photon mixing method and system based on local oscillator frequency doubling, and belongs to the fields of optical communication and microwave photonics. The microwave photon mixing system based on local oscillator frequency doubling is formed by utilizing a double-polarization double-parallel mach-zehnder modulator through combination with devices such as a laser, a front polarization controller, a microwave 90-degree coupler, a rear polarization controller, an optical fiber polarizer, an adjustable optical band-pass filter, an erbium-doped fiber amplifier,a photoelectric detector and the like. The system adopts second-order local oscillator sideband and first-order radio frequency sideband beat frequencies, and mixing processing based on local oscillator frequency doubling can be realized; on one hand, the frequency requirement of a mixing system on a local oscillator signal is reduced, and on the other hand, due to the fact that a single-sidebandmodulation mode is adopted, stray signals can be effectively reduced. In addition, the mixing method can realize switching of up conversion and down conversion by changing a direct current bias voltage, and can be used for time-sharing transmitting and receiving of radio frequency.

The invention relates to a 1.7micron fiber laser amplifier which structurally mainly comprises a signal source, an optical isolator, a pumped source, two wavelength division multiplexers, three thulium doped quartz fiber segments, two band pass filters separating the three thulium doped quartz fiber segments, a fiber bragg grating (FBG) and a fiber jumper wire head. The problems of signal gain saturation caused by ASE in the central wavelength position and severe signal light re-absorption in the 1.7micron short-wavelength operation process of the thulium doped fiber amplifier can be solved effectively, and output of 1.7micron-waveband amplification signals is stable and efficient.

The invention discloses a high-temperature superconducting transceiver subsystem which is packaged in a refrigerating machine in vacuum to keep operating temperature to be lower than transformation temperature of a superconducting material. The system comprises three radio frequency ports, a high-power superconducting filter, a circulator and a receiving channel. The system is applied to a wireless system for transmitting / receiving a wireless signal by a transmitter and a receiver respectively, thus achieving the purpose of receiving and transmitting the wireless signal simultaneously.